Process and apparatus for manufacturing a composite fire product and product resulting therefrom

ABSTRACT

A method of manufacturing a composite fire product comprising mixing materials, that include wax, at least one dry material and at least one non-dry material with a moisture content of at least 15%, blending and heating the mixed materials, compressing and heating the blended mixture, the compression pressure being at least 500 psi and the temperature being at least 100 F, and extruding the compressed mixture to form the composite fire product.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefits of U.S. provisional patent application No. 61/272,127 filed Aug. 19, 2009, which is hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to a process and apparatus for manufacturing a composited fire log resulting therefrom.

BACKGROUND

Commonly available composite fire logs and fire starter logs mainly comprise only one or two dry materials with wax or binders processed under very high pressures at generally ambient temperature These types of composite fire logs are limited as to their possible BTU output as well as possible raw materials and moisture content of the raw materials.

Accordingly, there is a need for a process for making composite fire logs and fire starter logs that does not require high pressures, that may use raw materials with high moisture content, which characteristically have not been used due to their low BTU value or cost of drying materials, while having a high BTU output.

SUMMARY

The present invention relates to a method of manufacturing a composite fire product, comprising:

-   -   a) blending and heating materials, the materials including wax,         at least one dry material and at least one non-dry material with         a moisture content of at least 15%;     -   b) compressing and heating the blended mixture, the compression         pressure being at least 500 psi and the temperature being at         least 100 F; and     -   c) extruding the compressed mixture to form the composite fire         product;         wherein at least one of the dry material and non-dry material         contains cellulose.

The present invention further relates to an apparatus for manufacturing a composite fire product, comprising:

-   -   a first pressure chamber having a heater;     -   a material composition receiving input having a feeding         mechanism for providing the material composition to the first         pressure chamber; and     -   a second pressure chamber having a temperature adjustment         mechanism and an extrusion output for providing the composite         fire product, the first and second pressure chambers being         operatively connected so as to allow material to pass         therebetween;         wherein the first and second pressure chambers are configured so         as to provide a pressure ranging from 500 psi to 25,000 psi and         the heater is configured so as to provide a temperature of at         least 100 F.

BRIEF DESCRIPTION OF THE FIGURES

Embodiments of the invention will be described by way of example only with reference to the accompanying drawing, in which:

FIG. 1 is a flow diagram of an illustrative example of the composite fire log manufacturing process; and

FIG. 2 is a schematic diagram of an illustrative example of the composite fire log manufacturing apparatus.

DETAILED DESCRIPTION

Generally stated, the non-limitative illustrative embodiment of the present invention provides for the manufacturing of a composite fire product using low BTU components having high moisture content. The non-limitative illustrative embodiment also provides for a low pressure apparatus that may be used for the manufacturing of the composite fire product. The resulting product is a dense composite fire product with a high BTU output. This is due to the combination of cellulose containing materials, blending dry materials with higher moisture content raw materials under high flash heat allowing the materials to flow more like liquids, form an adhesive interacting between the various components and combine to produce a uniform composition.

It is to be understood that the term “composite fire product” as used throughout the following description is not meant to be limitative and that it may also apply to other composite fire products such as, for example, fire logs, fire starter logs, pellets, etc.

Manufacturing Process

Referring to FIG. 1, there is shown a flow diagram of an illustrative example of the composite fire product manufacturing process. The steps of the process 10 are indicated by blocks 12 to 19.

The process 10 starts at block 12 where the various materials are mixed. The materials that may be used include wax (e.g. vegetable wax such as rice, palm, soy wax, advantageously having a melting point greater or equal to 100° F., or paraffin wax with similar properties), cardboard (wax cardboard and other waste paper), grains and spices, green residue waste (e.g. coffee grinds, tea leaves, sunflower hulls and stocks, waste flowers, soy bean hulls and stocks, straw (such as wheat, barley, oats, and soragum), citrus fruit peels, corn starch, stocks, husks, and cob; grass (hay), sugar cane (or similar large grass species) and saw dust or wood residues (softwood, hardwood, wood waste trimmings; leaves and components from spice plants, aromatic trees like cinnamon and evergreen trees in order to provide additional nature scent). The materials may also include waste streams containing high moisture content (i.e. greater or equal to 15%) from paper such as industrial pulp and paper waste, wax boxes, failed quality paper and wax paper batches. Further materials that may be used include industrial food baking raw materials that have failed quality control testing (flour, sugar, starch additives), as well as waste streams from the brewing industry.

It is to be understood that other materials with characteristics similar to the materials mentioned above may also be used.

In a first illustrative embodiment of the present invention, the materials include wax, at least one non-dry material having high moisture content (from 15 to 50%) and at least one dry material, with either or both the non-dry and dry materials containing cellulose.

In a second illustrative embodiment of the present invention, the proportion of each material may vary as follows:

-   -   wax in a proportion from about 1 to 50%;     -   high moisture content non-dry materials from about 5 to 75%, the         materials having a moisture content between 15 and 50%; and     -   dry materials in a proportion from about 5 to 75%.

In a third illustrative embodiment of the present invention, the proportion of each material may vary as follows:

-   -   wax in a proportion from about 1 to 50%;     -   cardboard in a proportion from about 5 to 75%;     -   green residue waste in a proportion from about 5 to 75%,         containing one or more green residue component with a moisture         content between 25 and 50%; and     -   saw dust or wood residue in a proportion from about 5 to 50%.

The dry materials are first mixed (i.e. cardboard, dry green residue waste, saw dust, wood, etc.) in no specific order. The wax can be dry and added to the dry material mix or melted and then added to complete the composition. The non-dry materials can be added to the wax and heated, mixed, and kept at a temperature greater or equal to about 100° F. until used in the mix.

At block 14, the mixed materials are blended to provide a consistent composition at ambient or elevated temperature (greater or equal to about 100° F.). The blending time, commonly from 5 to 30 minutes, is based on the specific materials in the mixture.

Then, at block 16, the composition is compressed and heated. The composition is compressed using, for example, a screw extruder or a packed compression device, at a pressure ranging from about 500 psi to 25,000 psi; advantageously under about 5,000 psi, depending on the composition and desired product (e.g. an easy to light fire starter having a lower density, a long lasting fire log having a high density, etc.). The temperature during the compression is advantageously kept greater or equal to about 100° F. and depends on the composition and the desired product as the core of the composition should be at a temperature greater or equal to about 120° F. The temperature typically ranges from about 100 to 400° F. The high temperature allows for the extraction or release of the natural binder in the green residue waste and wood residue components, and the pressure provides for a fluidity of the components to allow for a production a single mix component at the end of the process 10. The combination of high temperature with the mixture allows the use of lower pressures to produce higher density components at greatly reduced energy input. The pressure and temperature are applied to the mixed materials at flash times (i.e. below one minute).

At block 18, the compressed composition is extruded while being heated if a low density product is desired (for example to be formed into a specific shape by a further process) or cooled if a higher density product is desired (the cooling providing for an instant adhesive effect of the components). During the heated extrusion process, the temperature may range from 50 to about 75° F., the temperature varying with the size of die used in the extrusion, the components used in the composition and the desired density. During the cooled extrusion process, the temperature may range from ambient temperature to about 32° F., the drop in temperature varying with the size of die used in the extrusion, the components used in the composition and the desired density. The pressure and temperature are applied to the composition at flash times (i.e. below one minute). The conclusion of this step results in the composite fire product with a density varying according to the temperature at which the composition was extruded.

Finally, at block 19, as an optional step, the shape of the composite fire product may be modified depending on its intended use. As high density logs are harder to light than low density ones, at least one of the extremities of the composite fire product may be cut at an angle, for example between about 10 and 80°, so as to acts like a wick on a candle. This allows even a dense composite fire product to light easily. In an alternative illustrative embodiment, the composite fire product has at least one of its extremities cut at a 45° angle.

Because of the pressures used, the output of the composite fire product manufacturing process 10 may range up to 10 tons per hour while previous manufacturing methods using higher pressures in excess of 20,000 psi, and comparable capacity apparatuses, provide for only up to 1.5 tons per hour.

It is to be understood that as the diameter of the produced composite fire product increases, the duration of the compression and heating/cooling steps (steps 16 and 18), as well as the pressures applied, will need to be adjusted relative to the diameter of the desired composite fire product so as to allow for the temperature of its core to be consistently greater or equal to about 120° F.

Typical composite fire products manufactured in accordance with the composite fire product manufacturing process 10 of FIG. 1 were evaluated in a standard wood stove, with the following results:

-   -   a 0.3 oz composite fire product can burn up to about 40 minutes,         with a significant increase in BTU over that of natural wood         logs;     -   a 0.5 lb composite fire product can burn up to about 2 hours,         with a significant increase in BTU over that of natural wood         logs;     -   a 1.0 lb composite fire product can burn up to about 3 hours,         with a significant increase in BTU over that of natural wood         logs;     -   a 4.0 lbs composite fire product can burn up to about 4 hours,         with significant increase in BTU over that of natural wood logs;         and     -   a 8.0 lbs composite fire product can burn up to about 8 hours,         with a significant increase in BTU over that of natural wood         logs.

It should be noted that the composite materials of the composite fire product burn as one unit similarly to a coal briquette, not like the prior art products such as fire logs, which expand and break up while burning. Also, the use of wax in the composition and the processing of the components of the composition provide for composite fire products that are waterproof, therefore minimizing oxidation of the green residue materials. Also, the burning characteristic of the composite fire product allows for a more complete burning of the composite materials due to the increase BTU output (temperatures greater than 700° F.), which provides for a cleaner burn than firewood and leave less ash unlike prior art products.

It is to be understood that although the composite fire product manufacturing process 10 herein described allows the use of low pressures, it may also be used at high pressures as well.

Manufacturing Apparatus

Referring to FIG. 2, there is shown the schematic diagram of an illustrative example of the composite fire product manufacturing apparatus 100 that may be used to implement the composite fire product manufacturing process 10 of FIG. 1. The apparatus 100 is generally composed of a blending unit 120, a composition receiving unit 130 and two in-line temperature controlled pressure chambers 140, 150.

The blending unit 120 is adapted to receive the mixed materials and is provided with a blending mechanism 122, a conveyor 124 and a heating element 126. The conveyor 124 provides the blended composition of materials to the composition receiving unit 130.

The composition receiving unit 130 is adapted to receive the composition from the conveyor 124 and is provided with a feeding mechanism in the form of a feed screw 132, which activated by motor 134, and a heating element 136. The action of the feed screw 132 moves the composition into the first pressure chamber 140.

The first pressure chamber 140 comprises a pressurizing mechanism in the form of compression screw 142, which is also activated by motor 134, and a heating element 144. The speed of the motor 134 and the configuration of the compression screw 142 may be adjusted in order to control the pressure applied to the composition. It is to be understood that the dimensions of pressure chamber 140 also have an effect on the pressure. The action of the compression screw 142 moves the heated and pressurized composition into the second pressure chamber 150.

The second pressure chamber 150 comprises an extrusion output in the form of a die 152, through which the composition is extruded, and includes a temperature adjustment mechanism in the form of heating/cooling element 154. The die 152 may be adjusted depending on the desired product (e.g. fire log, fire starter log or pellet).

Optionally, the extrusion output may further include a slicing mechanism so as to cut at least one of the extremities of the composite fire product at an angle.

It is to be understood that, although not shown, the composite fire product manufacturing apparatus 100 also includes controls and power supply appropriate for its functioning, as known by a person skilled in the art.

Although the present invention has been described by way of particular embodiments and examples thereof, it should be noted that it will be apparent to persons skilled in the art that modifications may be applied to the present particular embodiment without departing from the scope of the present invention. 

What is claimed is:
 1. A method of manufacturing a composite fire product, comprising: a) blending and heating materials, the materials including wax, at least one dry material and at least one non-dry material with a moisture content of at least 15%; b) compressing and heating the blended mixture, the compression pressure being at least 500 psi and the temperature being at least 100 F; and c) extruding the compressed mixture to form the composite fire product; wherein at least one of the dry material and non-dry material contains cellulose.
 2. The method of claim 1, wherein the step a) is performed at a temperature of at least 100 F.
 3. The method of either of claim 1 or 2, wherein the step a) is performed for a duration of 5 to 30 minutes.
 4. The method of any of claims 1 to 3, wherein the pressure at step b) ranges from 500 psi to 25,000 psi.
 5. The method of claim 4, wherein the pressure at step b) ranges from 500 psi to 5,000 psi.
 6. The method of any of claims 1 to 5, wherein the temperature at step b) is at least 120 F.
 7. The method of any of claims 1 to 5, wherein the temperature at step b) ranges from 100 F to 400 F.
 8. The method of any of claims 1 to 7, wherein the step b) is performed for a duration of less than or equal to 1 minute.
 9. The method of any of claims 1 to 8, wherein step c) is performed at a temperature ranging from ambient temperature to 32 F.
 10. The method of any of claims 1 to 8, wherein step c) is performed at a temperature ranging from 50 to 75 F.
 11. The method of any of claims 1 to 7, wherein the step c) is performed for a duration of less than or equal to 1 minute.
 12. The method of any of claims 1 to 11, further comprising: d) shaping the composite fire product.
 13. The method of claim 12, wherein step d) consist in cutting at least one extremity of the composite fire product at an angle between 10 and 80°.
 14. The method of claim 13, wherein the angle is 45°.
 15. The method of any of claims 1 to 14, wherein the at least one dry material is selected from a group consisting of cardboard, wax, waste paper, dry green residue waste, saw dust and wood residue.
 16. The method of claim 15, wherein the wood residue is selected from a group consisting of softwood, hardwood and wood waste trimmings.
 17. The method of any of claims 1 to 16, wherein the wax has a melting point of at least 100 F.
 18. The method of any of claims 1 to 17, wherein the at least one non-dry material selected from a group consisting of wet waste streams and non-dry green residue waste.
 19. The method of claim 18, wherein the wet waste streams is selected from a group consisting of paper pulp, corn stalks, coffee grounds, Christmas trees and waste flowers.
 20. The method of claim 18, wherein the non-dry green residue waste is selected from the group consisting of coffee grinds, tea leaves, sunflower hulls, sunflower stocks, soy bean hulls, soy bean stocks, straw, citrus fruit peels, corn stocks, corn husks, corn cob; grass, hay, sugar cane, industrial pulp and paper waste.
 21. The method of any of claims 1 to 20, wherein the at least one non-dry material has a moisture content of at least 25%.
 22. The method of claim 21, wherein the at least one non-dry material has a moisture content lower or equal to 50%.
 23. The method of any of claims 1 to 22, further comprising heating the non-dry materials at a temperature of at least 100 F prior to step a).
 24. The method of any of claims 1 to 23, wherein the materials comprise wax in a proportion from 1 to 50%, wax cardboard, cardboard, waste paper or pulp in a proportion from 5 to 75%, green residue wastes in a proportion from 5 to 75% and saw dust or wood residue in a proportion from 5 to 75%.
 25. The method of any of claims 1 to 24, wherein the materials further include leaves and components from aromatic trees or spices in order to provide additional nature scent.
 26. A composite fire product manufactured by the method of any of claims 1 to
 25. 27. An apparatus for manufacturing a composite fire product, comprising: a first pressure chamber having a heater; a material composition receiving input having a feeding mechanism for providing the material composition to the first pressure chamber; and a second pressure chamber having a temperature adjustment mechanism and an extrusion output for providing the composite fire product, the first and second pressure chambers being operatively connected so as to allow material to pass therebetween; wherein the first and second pressure chambers are configured so as to provide a pressure ranging from 500 psi to 25,000 psi and the heater is configured so as to provide a temperature of at least 100 F.
 28. The apparatus of claim 27, wherein first and second pressure chambers are configured so as to provide a pressure ranging from 500 psi to 5,000 psi.
 29. The apparatus of either of claim 27 or 28, wherein the heater is configured so as to provide a temperature of at least 120 F.
 30. The apparatus of any of claims 27 to 29, wherein the heater is configured so as to provide a temperature ranging from 100 F to 400 F.
 31. The apparatus of any of claims 27 to 30, wherein the temperature adjustment mechanism is configured so as to provide a temperature ranging from 50 to 75 F.
 32. The apparatus of any of claims 27 to 30, wherein the temperature adjustment mechanism is configured so as to provide a temperature ranging from ambient temperature to 32 F.
 33. The apparatus of any of claims 27 to 32, wherein the extrusion output is in the form of a die.
 34. The apparatus of any of claims 27 to 32, wherein the extrusion output is configured so as to shape the extruded composite fire product.
 35. The apparatus of any of claims 27 to 34, wherein the feeding mechanism is a feeding screw.
 36. The apparatus of claim 35, further comprising a compression screw operatively connected to the feeding screw so to provide the pressure for the first and second pressure chambers.
 37. The apparatus of any of claims 27 to 36, wherein the extrusion output includes a slicing mechanism so as to cut at least one of the extremities of the composite fire product at an angle.
 38. The apparatus of any of claims 27 to 37, further comprising a blender adapted to receive mixed materials and providing the material composition to the receiving input by blending the mixed materials.
 39. The apparatus of claim 38, wherein the blender includes a heater. 